There is a place for contempt in our public discourse. We should have contempt for a regime in North Korea that brutalized a young American student named Otto Warmbier. We should have contempt for a regime in Syria that uses poison gas to massacre innocent men, women and children. We should have contempt for Islamic State terrorists who behead Americans, burn people alive in cages and systematically rape Yazidi girls.

But we should not have contempt for each other.

Yet, we do. Our politics today is descending into a bitter spiral of contempt. And we saw the consequences in the attempted assassination of Republican members of Congress on a baseball field in Alexandria, Virginia, last week. Back when Rep. Gabrielle Giffords, D-Ariz., was shot in 2011, many on the left were quick to blame conservative political rhetoric - falsely it turned out. But the attack on Rep. Steve Scalise, R-La., and his colleagues was politically motivated. The assassin volunteered for Sen. Bernie Sanders, I-Vt., called President Trump a "traitor" on social media and, according to witnesses, asked if the players were Republicans before opening fire.

No one is responsible except the would-be assassin. But his actions should serve as a wake-up call that the demonization of our fellow Americans who disagree with us has gone too far. The culture of contempt permeating our politics has now had near-fatal consequences. We need to put on the brakes and learn how to distinguish once again between our opponents and our enemies.

Case in point: A few weeks before the Alexandria shooting, Hillary Clinton gave a commencement speech at Wellesley College where she declared that Trump's budget is "an attack of unimaginable cruelty on the most vulnerable among us, the youngest, the oldest, the poorest." No, it is not. Using nerve agent on the innocent is "an attack of unimaginable cruelty." Putting a hapless college student into a coma is an "attack of unimaginable cruelty." Reducing the growth of government spending is not.

Think for a moment what Clinton was saying: It's not simply that Democrats and Republicans have an honest disagreement about how best to help the most vulnerable among us. In Clinton's telling, Republicans are waging war on the vulnerable. That is toxic.

No doubt, Trump has contributed mightily to our descent into the culture of contempt. (For example, the media is not the "enemy of the American people," Mr. President). But since Trump's election, the scope and scale of political contempt on the left have reached unprecedented heights. Just a few months ago, when President Barack Obama was in office, it would have been unimaginable for a comedian to proudly pose for a photo holding up the president's bloody, severed head.

Worst of all, we are in the process of cementing these attitudes in the next generation. On college campuses, students are being taught that it is acceptable to treat with contempt those with different ideas. We saw this phenomenon on display when Charles Murray - a distinguished conservative scholar - was shouted down and assaulted at Middlebury College in a riot that sent a professor to the hospital. Not a single student suffered any real consequences. Similar incidents are taking place on campuses across the country. Young Americans are learning that people they disagree with are not to be listened to respectfully and debated; they are to be silenced and driven out of the public square.

This is not to suggest that there is no role for righteous anger in political discourse. Conservatives felt anger about many of Obama's policies, and liberals have every right to be angry about Trump's policies they find objectionable. And they have every right to fight like hell to stop them.

But it wasn't so long ago that, despite bitter differences over policies, Republicans and Democrats still found ways to work together. President Bill Clinton and Republicans in Congress worked together to pass NAFTA and welfare reform. George W. Bush and congressional Democrats cooperated to pass tax cuts and education reform. Today, that kind of cooperation is unimaginable.

And the reason is simple: When anger transforms into contempt, permanent damage takes place. As American Enterprise Institute President Arthur C. Brooks points out, a marriage can recover from anger. But when couples become contemptuous of each other, they will almost certainly end up in divorce court. That is where our country is headed today.

Liberals need to understand: When they show contempt for Trump, they are expressing contempt for the millions of Americans who voted for him - including millions who twice voted for Obama. These Americans felt that the establishments of both parties were ignoring them and wanted to send Washington a message. The response they are receiving could not be clearer: We have contempt for the man you elected, and we have contempt for all of you who put him into office. They will never forget it.

We need to pull back from this spiral of contempt before it is too late. North Korea is our enemy. Our fellow Americans who disagree with us are not. It's time we learn the difference - before someone gets killed.